Using the spectrum of dark radiation as a probe of reheating

After inflation the Universe presumably undergoes a phase of reheating which in effect starts the thermal big bang cosmology. However, so far we have very little direct experimental or observational evidence of this important phase of the Universe. In this paper, we argue that measuring the spectrum...

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Bibliographic Details
Main Authors: Jaeckel, Joerg (Author) , Yin, Wen (Author)
Format: Article (Journal)
Language:English
Published: 15June 2021
In: Physical review
Year: 2021, Volume: 103, Issue: 11, Pages: 1-13
ISSN:2470-0029
DOI:10.1103/PhysRevD.103.115019
Online Access:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/PhysRevD.103.115019
Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/PhysRevD.103.115019
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Author Notes:Joerg Jaeckel and Wen Yin
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Summary:After inflation the Universe presumably undergoes a phase of reheating which in effect starts the thermal big bang cosmology. However, so far we have very little direct experimental or observational evidence of this important phase of the Universe. In this paper, we argue that measuring the spectrum of freely propagating relativistic particles, i.e., dark radiation, produced during reheating may provide us with powerful information on the reheating phase. To demonstrate this possibility we consider a situation where the dark radiation is produced in the decays of heavy, nonrelativistic particles. We show that the spectrum crucially depends on whether the heavy particle once dominated the Universe or not. Characteristic features caused by the dependence on the number of the relativistic degrees of freedom may even allow to infer the temperature when the decay of the heavy particle occurred.
Item Description:Gesehen am 05.08.2021
Physical Description:Online Resource
ISSN:2470-0029
DOI:10.1103/PhysRevD.103.115019